Pulse motor

Abstract

A pulse motor comprises A-and C-phase coils wound on a common core with opposite polarities appearing on the core, B- and D-phase coils wound on a common core with opposite polarities appearing on the core, first, second, third and fourth switching transistors connected in series with A-, B-, and C-and D-phase coils, respectively, and a control signal for controlling respective conduction states of the first, second, third and fourth switching transistors to permit a sequential excitation of the A-and B-phase coils, B-and C-phase coils, C-and D-phase coils, and D-and A-phase coils in this order. After a predetermined time following a start of the turning-OFF of one of said first, second, third and fourth switching transistors another one of the first, second, third and fourth transistors is turned ON.

What is claimed is: 
     
       1. A pulse motor comprising: A- and C-phase coils wound on a common pole;   B- and D-phase coils wound on a common pole;   first, second, third and fourth switching means connected in series with the A-, B-, C- and D-phase coils, respectively, and having an ON state for passing current to the respective phase coils and an OFF state for blocking current to the respective phase coils; and   control means including means for generating phase control signals for controlling respective conduction states of said first, second, third and fourth switching means to permit a sequential excitation of the A-and B-phase coils, B-and C-phase coils, C-and D-phase coils, and D-and A-phase coils in this order and so as to excite the A, C coils and B, D coils to generate, respectively, oppositely directed magnetic fluxes, and delay means for, after a predetermined time following a start of a transition from said ON state to said OFF state of one of the first, second, third and fourth switching means in the respective phase switching operation time, changing the state of another one of said switching means from the OFF state to the ON state.   
     
     
       2. A pulse motor according to claim 1, wherein said delay means delays the phase control signals from said phase control signal generating means by said predetermined time, and said control means further comprises logic circuit means for supplying to the corresponding switching means an output signal corresponding to a logical product of the phase control signal from said phase control signals generating means and an output signal from said delay means. 
     
     
       3. A pulse motor according to claim 2, wherein said switching means is comprised of a transistor. 
     
     
       4. A pulse motor according to claim 2, wherein said phase control signal generating means comprises a data generator for generating a control signal and phase control data, and a first signal generator responsive to said control signal to generate a phase control signal corresponding to said phase control data. 
     
     
       5. A pulse motor according to claim 4, wherein said delay means comprises a delay circuit for delaying said control signal from said data generator, and a second signal generator responsive to an output signal from said delay circuit to generate a phase control signal corresponding to said phase control signal from said first signal generator. 
     
     
       6. A pulse motor according to claim 5, wherein said first and second signal generators are each comprised of a latch circuit. 
     
     
       7. A pulse motor according to claim 5, wherein said delay circuit is comprised of a monostable multivibrator. 
     
     
       8. A pulse motor according to claim 5, wherein said logic circuit includes AND gates for receiving phase signals from said first and second signal generators.